I am looking for D&H timetables from the 1980s. Specifically, 1983-1984 would be great. I see lots of 1960s timetables on EBay, as well as a fair amount of 1950s and occasionally 1970s. Nothing for the 1980s. Did they exist from the mid-1970s on, or should I be searching for early Guilford timetables?